The present invention relates to an improved product-dispensing container and to a method for preparing the same for filling.
Much concern has recently been shown over the possibly deleterious effects of fluorinated hydrocarbons upon the atmosphere. This concern has promoted the search for alternatives to the use of such materials to provide the expelling force in product-dispensing containers especially aerosol containers.
Among the proposed alternatives is the elastic bag concept, both with and without separate product-impervious liners. This concept is typified by Fowler et al, U.S. Pat. No. 3,981,415, wherein an elastomeric bag provides a contracting force on an inner, product-containing bag.
Unfortunately, use of such an expelling method presents problems associated with filling of the container in that energy must be stored in the bag by stretching the same, either prior to or during filling. Conventional filling equipment is incapable of extending the bag during the filling operation.
It is, therefore, a primary object of the present invention to provide a propellantless product-dispensing container which may be readily filled by conventional filling equipment. This is accomplished by a container wherein the elastic member is stretched prior to filling. More specifically, the elastic member is extended and releasably held in the extended state during the filling operation, whereby filling may be achieved at normal equipment operating pressure.
It is a further object to provide a propellantless product dispensing container as described above, which is simple and economical to produce. This is accomplished by a container wherein the elastic unit is extended to engagement with the base of the container body. Specifically, a projection is provided, on the bottom of the liner or the elastic unit, adapted to protrude through a passage in the container base. The projection is locked in this position by means releasable from without the container.